Predictors of local recurrence and piecemeal resection in duodenal underwater endoscopic mucosal resection

Underwater endoscopic mucosal resection (UEMR) has been widely adopted for the treatment of superficial nonampullary duodenal epithelial tumors (SNADETs). The aim of this study was to identify predictors of local recurrence and piecemeal resection in UEMR for SNADETs.

This is a retrospective single-center study. Patients who underwent UEMR for SNADETs between November 2017 and October 2024 were included. We documented clinicopathologic characteristics of patients and lesions, noted procedure-related outcomes, and evaluated local recurrence. Kaplan-Meier analysis was used to assess recurrence-free survival, and logistic regression analysis was performed to identify the predictors of piecemeal resection.

Among the 367 patients, the rate of piecemeal resection was 11.2%, and the rate of en bloc resection with histologically tumor-free horizontal and vertical margins (R0) was 65.1%. No intraoperative perforations occurred; intraoperative bleeding was observed in 1.9%. Kaplan-Meier analysis of recurrence-free survival showed significantly poorer outcomes in the piecemeal resection group than the en bloc resection group (log-rank test, P < .001; Wilcoxon test, P < .001). According to multivariate logistic regression analysis, each 1-mm increase in lesion size (odds ratio [OR], 1.20; 95% confidence interval [CI], 1.11-1.31; P < .001) and a flat macroscopic type (OR, 12.49; 95% CI, 1.45-107.98; P = .02) were significant independent predictors of piecemeal resection.

Piecemeal resection was a risk factor for local recurrence in UEMR for SNADETs. In addition, each 1-mm increase in lesion size and a flat macroscopic type were significant independent predictors of piecemeal resection.